Move a feature to experimental

Author: alexey-milovidov

CHANGELOG.md

@@ -33,21 +33,23 @@
 * Added an in-memory cache for deserialized vector similarity indexes. This should make repeated approximate nearest neighbor (ANN) search queries faster. The size of the new cache is controlled by server settings `vector_similarity_index_cache_size` and `vector_similarity_index_cache_max_entries`. This feature supersedes the skipping index cache feature of earlier releases. [#77905](https://github.com/ClickHouse/ClickHouse/pull/77905) ([Shankar Iyer](https://github.com/shankar-iyer)).
 * Support partition pruning in DeltaLake. [#78486](https://github.com/ClickHouse/ClickHouse/pull/78486) ([Kseniia Sumarokova](https://github.com/kssenii)).
 * Support for a background refresh in readonly `MergeTree` tables which allows querying updateable tables with an infinite amount of distributed readers (ClickHouse-native data lake). [#76467](https://github.com/ClickHouse/ClickHouse/pull/76467) ([Alexey Milovidov](https://github.com/alexey-milovidov)).
-* Support using custom disks to store databases metadata files. For example, you can attach an `Ordinary` database from `web` disk. [#77365](https://github.com/ClickHouse/ClickHouse/pull/77365) ([Tuan Pham Anh](https://github.com/tuanpach)).
+* Support using custom disks to store databases metadata files. Currently it can be configured only on a global server level. [#77365](https://github.com/ClickHouse/ClickHouse/pull/77365) ([Tuan Pham Anh](https://github.com/tuanpach)).
 * Support ALTER TABLE ... ATTACH|DETACH|MOVE|REPLACE PARTITION for the plain_rewritable disk. [#77406](https://github.com/ClickHouse/ClickHouse/pull/77406) ([Julia Kartseva](https://github.com/jkartseva)).
 * Add table settings for `SASL` configuration and credentials to the `Kafka` table engine. This allows configuring SASL-based authentication to Kafka and Kafka-compatible systems directly in the CREATE TABLE statement rather than having to use configuration files or named collections. [#78810](https://github.com/ClickHouse/ClickHouse/pull/78810) ([Christoph Wurm](https://github.com/cwurm)).
 * Allow setting `default_compression_codec` for MergeTree tables: it is used when the CREATE query does not explicitly define one for the given columns. This closes [#42005](https://github.com/ClickHouse/ClickHouse/issues/42005). [#66394](https://github.com/ClickHouse/ClickHouse/pull/66394) ([gvoelfin](https://github.com/gvoelfin)).
 * Add `bind_host` setting in the clusters configuration so that ClickHouse can use a specific network for distributed connections. [#74741](https://github.com/ClickHouse/ClickHouse/pull/74741) ([Todd Yocum](https://github.com/toddyocum)).
 * Introduce a new column, `parametrized_view_parameters` in `system.tables`. Closes https://github.com/clickhouse/clickhouse/issues/66756. [#75112](https://github.com/ClickHouse/ClickHouse/pull/75112) ([NamNguyenHoai](https://github.com/NamHoaiNguyen)).
 * Allow changing a database comment. Closes [#73351](https://github.com/ClickHouse/ClickHouse/issues/73351) ### Documentation entry for user-facing changes. [#75622](https://github.com/ClickHouse/ClickHouse/pull/75622) ([NamNguyenHoai](https://github.com/NamHoaiNguyen)).
 * Support `SCRAM-SHA-256` authentication in the PostgreSQL compatibility protocol. [#76839](https://github.com/ClickHouse/ClickHouse/pull/76839) ([scanhex12](https://github.com/scanhex12)).
-* Functions `sparseGrams` and `sparseGramsHashes` with ASCII and UTF8 versions added. Author: [scanhex12](https://github.com/scanhex12). [#78176](https://github.com/ClickHouse/ClickHouse/pull/78176) ([Pervakov Grigorii](https://github.com/GrigoryPervakov)).
 * Add functions `arrayLevenshteinDistance`, `arrayLevenshteinDistanceWeighted`, and `arraySimilarity`. [#77187](https://github.com/ClickHouse/ClickHouse/pull/77187) ([Mikhail f. Shiryaev](https://github.com/Felixoid)).
 * The setting `parallel_distributed_insert_select` makes effect for `INSERT SELECT` into `ReplicatedMergeTree` (previously it required Distribued tables). [#78041](https://github.com/ClickHouse/ClickHouse/pull/78041) ([Igor Nikonov](https://github.com/devcrafter)).
 * Introduce `toInterval` function. This function accepts 2 arguments (value and unit), and converts the value to a specific `Interval` type. [#78723](https://github.com/ClickHouse/ClickHouse/pull/78723) ([Andrew Davis](https://github.com/pulpdrew)).
-* Add several convenient ways to resolve root metadata.json file in an iceberg table function and engine. Closes [#78455](https://github.com/ClickHouse/ClickHouse/issues/78455). [#78475](https://github.com/ClickHouse/ClickHouse/pull/78475) ([Daniil Ivanik](https://github.com/divanik)).
+* Add several convenient ways to resolve root `metadata.json` file in an iceberg table function and engine. Closes [#78455](https://github.com/ClickHouse/ClickHouse/issues/78455). [#78475](https://github.com/ClickHouse/ClickHouse/pull/78475) ([Daniil Ivanik](https://github.com/divanik)).
 * Support password based auth in SSH protocol in ClickHouse. [#78586](https://github.com/ClickHouse/ClickHouse/pull/78586) ([Nikita Mikhaylov](https://github.com/nikitamikhaylov)).
 
+#### Experimental Feature
+* Functions `sparseGrams` and `sparseGramsHashes` with ASCII and UTF8 versions added. Author: [scanhex12](https://github.com/scanhex12). [#78176](https://github.com/ClickHouse/ClickHouse/pull/78176) ([Pervakov Grigorii](https://github.com/GrigoryPervakov)). Do not use it: the implementation will change in the next versions.
+
 #### Performance Improvement
 * Optimize performance with lazy columns, that read the data after ORDER BY and LIMIT. [#55518](https://github.com/ClickHouse/ClickHouse/pull/55518) ([Xiaozhe Yu](https://github.com/wudidapaopao)).
 * Enabled the query condition cache by default. [#79080](https://github.com/ClickHouse/ClickHouse/pull/79080) ([Alexey Milovidov](https://github.com/alexey-milovidov)).